The field of the disclosure relates generally to a device for use in inspecting an air gap between two surfaces and, more particularly, to an inspection apparatus and control system for use with an inspection probe fixed to an extendable structure.
Machines, motors, and industrial equipment are generally inspected regularly to ensure proper function and operation, particularly long-life cycle equipment. Surfaces of turbine, boiler, and generator components, for example, are inspected for damage to prevent failure or damage during operation. In generators, for example, stator and rotor surfaces may be inspected via a narrow air gap defined between the stator and rotor using an inspection probe that is extended into the air gap without disassembling the generator, thus saving time, effort, and generator downtime for inspection.
For certain equipment, an inspection probe is fixed to an extendable structure that is guided into the air gap via a motor. In generators, for example, where the stator is ferromagnetic, the extendable structure includes one or more magnets that maintain contact with the stator via a magnetic adhesion as the inspection probe and extendable structure are extended into the air gap. The extendable structure provides support for the inspection probe as it is driven by the motor, extending into the air gap without bends or arches, and with a generally constant separation between the inspection probe and the stator. Certain structures, such as a steel band or tape, for example, are collected outside the air gap, in a roll for example. Extension and retraction of the steel band amounts to unrolling and rolling the steel band by the motor.